1 files changed, 52 insertions, 0 deletions
diff --git a/backend/include/rcc/CodeGen/ReachingDefAnalysis.h b/backend/include/rcc/CodeGen/ReachingDefAnalysis.h
new file mode 100644
index 0000000..64eb462
--- /dev/null
+++ b/backend/include/rcc/CodeGen/ReachingDefAnalysis.h
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_REACHINGDEFANALYSIS_H
+#define RCC_CODEGEN_REACHINGDEFANALYSIS_H
+
+#include "rcc/CodeGen/MachineFunctionAnalysisManager.h"
+#include "rcc/Support/Error.h"
+
+#include <cstddef>
+#include <span>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class MachineOperand;
+class TargetDescription;
+
+class ReachingDefAnalysis final {
+public:
+  using DefinitionSet = std::vector<const MachineInstr *>;
+
+  class Result final {
+  public:
+    [[nodiscard]] std::span<const MachineInstr *const>
+    reachingDefinitions(const MachineOperand &Operand) const noexcept;
+    [[nodiscard]] std::size_t instructionNumber(const MachineInstr &Instruction) const noexcept;
+    [[nodiscard]] bool invalidate(const MachineFunction &,
+                                  const PreservedAnalyses &Preserved) const noexcept;
+
+  private:
+    std::unordered_map<const MachineOperand *, DefinitionSet> OperandDefinitions;
+    std::unordered_map<const MachineInstr *, std::size_t> InstructionNumbers;
+
+    friend class ReachingDefAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "ReachingDefAnalysis";
+  }
+
+  [[nodiscard]] static Expected<Result> run(MachineFunction &Function,
+                                            const TargetDescription &Target,
+                                            MachineFunctionAnalysisManager &Analyses);
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_REACHINGDEFANALYSIS_H